Sunday, September 29, 2013

With some prodding from a fellow homebrewer (you know who you are!), I have put together a simple spreadsheet for calculating mash pH. The equations used in the spreadsheet are discussed in the two papers introduced in the previous two posts of this blog. The spreadsheet is not unlike others that are out there (think EZ Water, Brun Water, and Kaiser Water), but it is not as extensive in that (for this first version, anyway), it only deals with estimating the pH of the mash. This does, however, make the spreadsheet quite simple and (I hope) quite straightforward to use.

One thing the sheet assumes is that you know the ion concentrations (in ppm) associated with your brewing water. If your water report does not give these in a straightforward manner, I suggest you search around on the web to first figure out how to convert your information to ppm of the individual ions.

The outline of the spreadsheet is as follows. From your grain bill and strike water volume, the pH that your mash would have if you were to use distilled water is calculated. Next the spreadsheet takes into account any ions in the strike water that can affect pH. These ions are Ca^(2+), Mg^(2+), and HCO_3^+. After this you can enter any salt additions that you wish, and pH is calculated again taking these into account. Lastly, you have the option of several acid additions that will also affect pH. The bottom-line pH value is your estimated pH. Along the way you may find the comments attached to various cells useful.

One feature you may find lacking is that this spreadsheet does not deal with CaCO_3 (chalk) additions. This is intentional. First, the addition of chalk is (i) really never necessary, and (ii) somewhat problematic in that chalk only fully dissolves in the presence of elevated CO_2 pressure. If you really needs to raise the HCO_3^- (bicarbonate) level of the brewing liquor, a little NaHCO_3 will go a long way, as the spreadsheet will calculate for you.

As always, thoughts, comments, and questions are always welcome. Cheers!

Monday, September 16, 2013

Here is the companion paper to my first paper on mash pH (see previous post). Entitled A Homebrewing Perspective on Mash pH II: Water, this paper continues with analysis of Kai Troester's experimental work mash pH, and along the way discusses some useful concepts such as residual alkalinity, ion concentration, and normality. Again, the three spreadsheets EZ Water,Brun Water, andKaiser Water are discussed. The paper ends with some suggestions for adjusting mash pH when starting with distilled or reverse osmosis water.As usual, thoughts, comments, and questions are all welcome. Cheers!

Sunday, September 8, 2013

Interested in what contributes to the pH of the mash? I was, and so I decided to do some research on the subject. Not original research in terms of collecting new data, but I have studied most (if not all) of Kai Troester's (KT) extensive experimental work on the subject. In the process I also came across several spreadsheet based calculators of mash pH (EZ Water, Brun Water, and Kaiser Water) that are available to the homebrewing community. The models used by these calculators for estimating mash pH are all largely based on KT's data. [I'll mention that there is also a similar spreadsheet by John Palmer, although (I believe) this spreadsheet predates the work of KT.]

In the process of my research I decided to analyze KT's data and from that build my own model of mash pH. I also wanted to understand what was going on (under the hood) of these other three calculators that are based on this same data. And so I have written two review papers (of sorts) that puts together my analysis and subsequent understanding of the subject in one spot (OK, two spots). Mostly I have written this up for myself, but I thought, why not share this with other homebrewers?